LARGE SIGNAL AMPLIFIER GAIN COMPENSATION CIRCUIT

摘要

A power amplifier to process an input signal includes an amplifying device operating at a quiescent point and a bias network that varies the quiescent point according to a frequency of the input signal. In a variant of this power amplifier, the bias network includes a compensation circuit to provide a bias signal that varies according to a frequency of the input signal and a bias circuit to vary the quiescent point according to the bias signal. In an alternative embodiment of the invention, a method of making a power amplifier includes steps of measuring a gain performance of an amplifying device at a plurality of frequencies, determining a desired quiescent point of the amplifying device at each frequency of the plurality of frequencies, and constructing a bias network that varies an operating quiescent point of the amplifying device according to a frequency of the input signal so that the operating quiescent point approximates the desired quiescent point at each frequency of the plurality of frequencies. In a variant of this method the step of determining determines the desired quiescent point to be an operating quiescent point at which the amplifying device dissipates a minimum power that is consistent with providing a gain performance within a specified range of gains.